Please note that this function is reserved for two arrays with continued numbers inside (just integers).I tested this function and found that it calculate the Pearson's Correlation Coefficient of two arrays.---Here's suggested documentation:

stats_stat_correlation — Calculate the Pearson's Correlation Coefficient of two arrays of continued numbers.

Parameters:arr1 = array (integer1a, interger2a ...)arr2 = array (integer1b, interger2b ...))(Note that the count of elements in two arrays must be equal)